[PDF] Fix printing crashes caused by font streams that don't support getMemoryBase().

src/pdf/SkPDFStream.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkData.h"
 #include "SkFlate.h"
 #include "SkPDFCatalog.h"
 #include "SkPDFStream.h"
 #include "SkStream.h"
 
 static bool skip_compression(SkPDFCatalog* catalog) {
     return SkToBool(catalog->getDocumentFlags() &
                     SkPDFDocument::kFavorSpeedOverSize_Flags);
 }
 
-SkPDFStream::SkPDFStream(SkStream* stream)
-    : fState(kUnused_State),
-      fData(stream) {
-    SkSafeRef(stream);
+SkPDFStream::SkPDFStream(SkStream* stream) : fState(kUnused_State) {
+    setData(stream);
 }
 
 SkPDFStream::SkPDFStream(SkData* data) : fState(kUnused_State) {
     setData(data);
 }
 
 SkPDFStream::SkPDFStream(const SkPDFStream& pdfStream)
         : SkPDFDict(),
-          fState(kUnused_State),
-          fData(pdfStream.fData.get()) {
-    fData.get()->ref();
+          fState(kUnused_State) {
+    setData(pdfStream.fData.get());
     bool removeLength = true;
     // Don't uncompress an already compressed stream, but we could.
     if (pdfStream.fState == kCompressed_State) {
         fState = kCompressed_State;
         removeLength = false;
     }
     SkPDFDict::Iter dict(pdfStream);
     SkPDFName* key;
     SkPDFObject* value;
     SkPDFName lengthName("Length");
@@ skipping 11 matching lines @@
                              bool indirect) {
     if (indirect) {
         return emitIndirectObject(stream, catalog);
     }
     if (!this->populate(catalog)) {
         return fSubstitute->emitObject(stream, catalog, indirect);
     }
 
     this->INHERITED::emitObject(stream, catalog, false);
     stream->writeText(" stream\n");
-    stream->write(fData->getMemoryBase(), fData->getLength());
+    stream->writeStream(fData.get(), fData->getLength());
+    fData->rewind();
     stream->writeText("\nendstream");
 }
 
 size_t SkPDFStream::getOutputSize(SkPDFCatalog* catalog, bool indirect) {
     if (indirect) {
         return getIndirectOutputSize(catalog);
     }
     if (!this->populate(catalog)) {
         return fSubstitute->getOutputSize(catalog, indirect);
     }
 
     return this->INHERITED::getOutputSize(catalog, false) +
         strlen(" stream\n\nendstream") + fData->getLength();
 }
 
 SkPDFStream::SkPDFStream() : fState(kUnused_State) {}
 
 void SkPDFStream::setData(SkData* data) {
     SkMemoryStream* stream = new SkMemoryStream;
     stream->setData(data);
     fData.reset(stream);  // Transfer ownership.
 }
 
 void SkPDFStream::setData(SkStream* stream) {
+    // Code assumes that the stream starts at the beginning and is rewindable.
+    if (stream) {
+        SkASSERT(stream->getPosition() == 0);
+        SkASSERT(stream->rewind());
+    }
     fData.reset(stream);
     SkSafeRef(stream);
 }
 
 bool SkPDFStream::populate(SkPDFCatalog* catalog) {
     if (fState == kUnused_State) {
         if (!skip_compression(catalog) && SkFlate::HaveFlate()) {
             SkDynamicMemoryWStream compressedData;
 
             SkAssertResult(SkFlate::Deflate(fData.get(), &compressedData));
@@ skipping 11 matching lines @@
     } else if (fState == kNoCompression_State && !skip_compression(catalog) &&
                SkFlate::HaveFlate()) {
         if (!fSubstitute.get()) {
             fSubstitute.reset(new SkPDFStream(*this));
             catalog->setSubstitute(this, fSubstitute.get());
         }
         return false;
     }
     return true;
 }